Northern Star Resources has struck a joint venture with Fortescue Metals Group to boost its gold exploration footprint between its Paulsens and Ashburton projects in the Pilbara.

Under the terms of the deal, Northern Star will be able to earn up to a 60 per cent interest in non-iron ore rights on FMG tenements by spending up to $6 million.

Northern Star will initially pay $2 million to FMG for a 25 per cent joint venture with the right to earn in a further 35 per cent by spending an extra $4 million within two years.

After that, FMG will have to co-contribute or dilute their interest to an eventual 2 per cent net smelter return.

Northern Star said the deal would give it access to about 400km of strike along two parallel structures with Paulsens and Mt Olympus situated at either end.

Northern Star managing director Bill Beament said the Fortescue tenements were the final pieces of the jigsaw, giving the company an extensive land holding in one of Australia's most prospective yet barely explored gold regions.

"Given the combination of the deposits we know about in this area and the lack of exploration undertaken, we believe this region boasts some of the most promising upside in the Australian gold industry," he said.

Northern Star has set aside $20 million for exploration in calendar year 2013.

"This will be used to continue growing resources at Paulsens, establishing a 100,000ozpa stand-alone operation at Ashburton and undertaking aggressive exploration activities on the newly acquired ground in addition to Electric Dingo, Belvedere and other prospects between Paulsens and Ashburton," the company said in a statement.